Abstract and Introduction
Background: the beneficial role of exercise in improving bone mineral density, muscle strength and balance, has been documented predominantly in younger populations. These findings may not apply to elderly populations with limited ability to perform exercises of high intensity.
Objective: to examine the effects of Tai Chi (TC) and resistance exercise (RTE) on bone mineral density (BMD), muscle strength, balance and flexibility in community living elderly people.
Design: randomised controlle trial, using blocked randomization with stratification by sex.
Setting: a community in the New Territories Region of Hong Kong, China.
Subjects: one hundred eighty subjects (90 men, 90 women) aged 65-74, were recruited through advertisements in community centres.
Methods: subjects were assigned to participate in TC, RTE three times a week, or no intervention (C) for 12 months. Measurements were carried out at baseline, 6 and 12 months. Analyses of covariance (ANCOVA) adjusted for age, and baseline values of variables that were significantly different between groups: i.e. smoking and flexibility for men; quadriceps strength for women.
Results: compliance was high (TC 81%, RTE 76%). In women, both TC and RTE groups had less BMD loss at total hip compared with controls. No effect was observed in men. No difference in either balance, flexibility or the number of falls was observed between either intervention or controls after 12 months.
Conclusion: the beneficial effects of TC or RTE on musculoskeletal health are modest and may not translate into better clinical outcomes.
Osteoporosis is occurring as an epidemic in the urbanised parts of Asia. For instance, in Hong Kong, 3 per 1,000 elderly men and women fracture their hip every year. A lack of physical activity and poor muscle strength were found to be important risk factors for hip fracture among the elderly.[2,3] Studies in Caucasian populations showed weight-bearing exercises to be effective in maintaining bone mineral density (BMD), and mixed type exercises for preventing falls. The impact of exercise on falls is likely to be mediated by improvement in leg muscle function,[6,7] faster neuromuscular reactions in leg muscles resulting in more efficient protection in postural disturbances, balance, particularly for exercises such as Tai Chi (TC),[9,10] and fear of falling.[10,11] Therefore, exercise is an important intervention in the maintenance of bone health, muscle strength and balance, thereby reducing the risk of falls and fractures. In elderly people, exercises of a strenuous or intense nature with documented evidence of health benefits may not be feasible. It has been suggested that TC is a suitable form of exercise in balance and leg strength training, while resistance exercise (RTE) is considered a key intervention in counteracting sarcopenia associated with ageing. The majority of previous studies on TC have examined the effect on falls, with conflicting results.[9,13,14,15,16,17] It is possible that less marked effects are observed with increasing frailty.[14,15] Few studies examined the effect of TC on BMD. Since TC is a weight-bearing exercise, a beneficial effect may be expected, and this is observed in postmenopausal women between 50 and 60 years of age.[18,19,20] However, the effect in elderly people is uncertain. Therefore, we conducted a randomised controlled trial comparing the effects of TC and RTE in community-living elderly people, to determine whether these are suitable exercise interventions for improving BMD, strength, balance and flexibility in terms of effectiveness and compliance.
Age Ageing. 2007;36(3):262-268. © 2007 Oxford University Press
Cite this: A Randomised Controlled Trial of Tai Chi and Resistance Exercise on Bone Health, Muscle Strength and Balance in Community-living Elderly People - Medscape - Mar 13, 2007.